JP5352920B2 - Method for producing silicone resin-coated titanium dioxide composite particles - Google Patents

Description

The present invention relates to a silicone resin coating titanium dioxide composite particles produced how, and more particularly, upon application to the skin cosmetics, whiteness and cover due to wetting of sebum present on the skin (wetting) preventing a reduction in force, it relates to a silicone resin coating titanium dioxide composite particles produced how to indicate a high hiding power without reducing Efficacy as a pigment titanium dioxide having a refractive index similar to sebum simultaneously.

  Particle design in cosmetic compositions means intentionally producing powder particles with a special spatial structure by rearranging various materials three-dimensionally in a particle-dimensional microspace. To do. Such particle design positively utilizes the characteristics of the particle bulk and the surface structure to improve the function of the particle and provide a new function.

  Conventionally, there are various methods for imparting hydrophobicity to the powder. It is known to use the hydrophobic nature of silicone oil.

  Human secretions, such as sweat, tears and sebum, cause makeup collapse. In particular, in the case of ultraviolet screening agents and makeup cosmetics, sebum secreted from the skin is added to the emulsion in which the cosmetics are blended, and the cosmetic powder is excessively wetted, resulting in makeup collapse. Therefore, attempts have been made to use volatile emulsions such as octamethylcyclotetrasiloxane and decamethylcyclopentasiloxane to reduce emulsions in cosmetics.

In addition, friction, water, and the like also cause makeup collapse. Therefore, in order to prevent makeup collapse caused by water-soluble substances such as sweat and tears, silicone oil having high water repellency is combined. For example, dimethylpolysiloxane has been recently used in cosmetics because it has features such as a light touch, excellent water repellency and high safety.
On the other hand, pigments such as titanium oxide, zinc oxide, and bengara, and powders such as mica and sericite, including basic cosmetics, are used in fields such as UV blockers, nail color, nail coat, foundation, mascara, eyeliner, and other cosmetics. Widely used in These powders are generally treated with aluminum oxide treatment, silica treatment, emulsion treatment, metal soap treatment, organopolysiloxane treatment to impart surface inactivation, water resistance, sebum resistance and the like.

Silicone compounds that can be used to provide hydrophobicity have an intramolecular organohydrogenpolysiloxane chain, sometimes an intramolecular 2 organopolysiloxane chain, or a mixture of organohydrogenpolysiloxane and 2 organopolysiloxane. Things.
If these compounds are coated on the surface of the powder, the Si-H group bonding portion of the organohydrogenpolysiloxane molecule is the surface activity of the powder, and the Si-OH groups generated by reacting with moisture in the air are other It reacts with Si—H groups of neighboring molecules, or Si—OH groups react spontaneously, crosslink and polymerize to form a silicone film.

  However, if the heat treatment is performed in air at about 200 ° C. after coating the organic water polysiloxane on the powder surface, the residual Si—H groups are not completely removed, but the cross-linking reaction of the molecule itself proceeds to some extent. On the other hand, when heated at 500 ° C. or higher, silicone begins to burn and changes to silica (refer to Patent Document 1, “Method of coating silicon oxide by heat treatment at a temperature of 600 ° C. to 950 ° C.)”.

  The residual Si—H group generates hydrogen in response to moisture in the air or moisture in the cosmetic product, alcohol, amine, etc. over a long period of time to form a new siloxane bond. When used in coating compositions, toners, inks, containers, and a variety of other composition components, many problems often arise with the compositions.

  For example, in the case of cosmetics, there is a risk that hydrogen is generated during the production process, and after filling the container with the product, the container may expand over time, the product is hard, Or it may break. In the case of coating compositions, container aging problems often occur.

  In order to reduce the above-described residual Si—H group, for example, Patent Document 2 (that is, Patent Document 3, “compound having an unsaturated hydrocarbon group by addition reaction of silicon hydride is added to the residual Si—H group”. Method "), Patent Document 4 (" Residation reaction of residual Si-H group by contact with water or lower alcohol "), Patent Document 5 (" Cross-linking of organohydrogenpolysiloxane using mechanochemical reaction and Attempts have been made to mix and grind a mixture of a metal hydroxide and a treated powder as a catalyst for the polymerization reaction.

  The above method is effective in itself, but the powder is unpleasant because the process is complex and requires a long period of time or a relatively active functional group is adsorbed on the surface.

  In addition, the technique of coating a silicone resin on powder is mainly dissolved in a solvent so that the coating is formed by bonding between reactive groups on the surface, but the coating amount is usually 2 to 3% by weight (up to 5% by weight). %), And when applied to cosmetics, there is a problem in that whiteness and covering power are reduced due to wetting of sebum on the skin when applied to cosmetics.

JP-A-11-199458 JP-A-63-113081 Japanese Patent No. 1635593 JP-A-8-192101 Japanese Examined Patent Publication No. 56-043264

The present invention has been made in view of the above points, and an object of the present invention is to coat titanium dioxide particles with polymethylsilsesquioxane, which is a silicone resin having a refractive index similar to sebum. and to provide a granulation how made of silicone resin-coated titanium dioxide composite particles child.

  The method for producing silicone resin-coated titanium dioxide composite particles according to the present invention includes (1) a first raw material preparation stage in which titanium dioxide is dispersed in water to prepare a first raw material, and (2) polymethylsilsesquioxane is alkalinized. A second raw material preparation step of preparing a second raw material by dissolving in an aqueous solution; (3) charging the second raw material into the first raw material and stirring for 3 to 4 hours in a temperature range of 50 to 70 ° C. A first reaction stage for heating, (4) a second reaction stage for introducing an acid aqueous solution into the product obtained from the first reaction stage and polymerizing, and (5) 20 to 30 hours after the reaction. And a post-treatment stage that is washed with water, filtered, dehydrated, dried and pulverized.

  The alkaline aqueous solution in the second raw material preparation stage is preferably a sodium hydroxide aqueous solution having a concentration of 10 to 20%.

  The solid powder content of the second raw material obtained from the second raw material preparation stage is preferably 5 to 15% by weight.

  In the second reaction stage, the aqueous acid solution is preferably an aqueous hydrochloric acid solution having a concentration of 30 to 40%.

Therefore, according to the present invention, when cosmetics are applied to the skin, titanium dioxide having a refractive index similar to that of sebum while preventing a decrease in whiteness and covering power due to wetting of sebum existing in the skin. providing the silicone resin coating titanium dioxide composite particles produced how showing a high hiding power without reducing Efficacy as a pigment.

The result of the particle size analysis for comparing the particle size of the composite particles of Example 1 of the present invention and the uncoated titanium dioxide (Comparative Example 1) used in the production of the first raw material in Example 1 is shown. It is a graph. The morphology of the composite particles of Example 1 of the present invention and the particles of uncoated titanium dioxide (Comparative Example 1) used in the production of the first raw material in Example 1 were analyzed with a scanning electron microscope (SEM). It is a photograph which shows a result. Only the composite particles of Example 1 of the present invention and the polymethylsilsesquioxane used in the production of the second raw material in Example 1 above (TOSPARAL 2000B from Toshiba). 4 is a graph showing a result of confirming whether or not a PMSQ envelope can be formed through thermal analysis (FIG. 3) of the particles (Comparative Example 2). Only the composite particles of Example 1 of the present invention and the polymethylsilsesquioxane used in the production of the second raw material in Example 1 above (TOSPARAL 2000B from Toshiba). 5 is a graph showing a result of confirming whether or not a PMSQ envelope can be formed through infrared spectroscopic analysis (FIG. 4) of particles (Comparative Example 2). In order to measure the change in optical properties due to wetting of the sebum component, Example 1 and Comparative Example 1 of the present invention were used as they were, and CTG (capryl / caprylic triglyceride) as the main component of sebum was used. It is a graph showing the result of having measured the change of the reflectance by combining with the quantity of% and 16%, and wetting by CTG. A non-coated titanium dioxide with in vitro SPF and a titanium dioxide coated with 25% of polymethylsilsesquioxane in the same amount (10%) are used to make a san- chrome, and the UV blocking value is obtained using the in vitro test method. It is a data sheet showing specific data.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings to such an extent that those skilled in the art can easily implement the present invention.

  The silicone resin-coated titanium dioxide composite particles according to the present invention are composed of a core composed of titanium dioxide particles and an outer shell surrounding the core, and the outer sheath is composed of polymethylsilsesquioxane. And That is, the composite particles according to the present invention have titanium dioxide, which is one of the typical materials widely used in cosmetic compositions, as a core, and is wrapped with polymethylsilsesquioxane having a refractive index similar to sebum. Composed.

  The polymethylsilsesquioxane has a main chain skeleton formed in a siloxane structure such as silica that is not a hydrocarbon such as an organic polymer, and also exhibits processability like an organic polymer. This is a polysiloxane system with a high degree of cross-linking, and the cross-linking of the silicone resin is obtained on the basis of trifunctional or tetrafunctional silanes. A material having 1.5 oxygen molecules per silicone molecule in the silicone resin is polysilsesquioxane. In general, a network structure of a silicone resin can be represented by the following chemical formula 1.

  In the above formula, R is an alkyl or phenyl group, R—Si has an organic structure, and Si—O / Si—OH has a characteristic of a unique inorganic polymer having an inorganic structure. Among such silicone resins, the case where R is a methyl group is polymethylsilsesquioxane (PMSQ; polymethylsilsesquioxane). The surface R-Si / Si-OH ratio, that is, n / mql of the above structural formula is adjusted according to the PMSQ generation conditions, and m is increased under the composite conditions so that various surface treatments can be performed after the composite particles are generated. To.

  The types of PMSQ appear in Table 1 below.

Polysilsesquioxane was originally commercialized by Owens Illinois and Gelest under the name of “Glass Resin” and “SST Resin” since it was first synthesized by Brown, etc. of GE, USA. However, it is difficult to control the structure of the polymer, adjust the molecular weight, and increase the molecular weight, and has not yet been directly applied to industrial materials. However, recently, as the performance limit of the conventional organic polymer is overcome or the demand for new functions increases rapidly, the demand for practical use has increased. This material is used as a silicone resin (silicone oil) in cosmetics.
There are three types of materials having siloxane structural units (Si-O-Si): M, D, and Q. Polysiloxanes represented by the general formula (RSiO3 / 2) n are represented by a structure of T units. It is called Rusesquioxane (Polysilsesquioxane). Among them, resin materials obtained through a high molecular weight reaction such as polymerization are Q, T, and D.
Since Q has a resin with an irregular network structure formed through four linking groups (siloxane), it has excellent heat resistance and poor processability, and D is linear through two linking groups. Since a resin having a structure is formed, the heat resistance is poor, but the processability is excellent. On the other hand, T is composed of three bonding groups, so that it is possible to combine the advantages of Q or D by reaction control.

  In addition, since polysilsesquioxane can introduce an organic functional group through the remaining linking group that does not have a siloxane bond, the functionality of the organic polymer such as photocuring property can be imparted through this. .

Mainly, silsesquioxane polymers that have been developed and researched to date have various types such as hydrogen, alkyl, alkylene, aryl, arylene, and organic functional groups depending on the substituent R. Until now, polymethylsilsesquioxane, polyphenylsilsesquioxane, polyhydrogensilsesquioxane, and the like have been actively studied for imparting excellent thermo-mechanical properties.
In the case of heat resistance, the thermal stability is excellent and the initial thermal decomposition temperature is 400 ° C. or higher, which is about 50 ° C. higher than the initial thermal decomposition temperature of polyimide known as a high heat resistant polymer among organic polymers. More expensive. On the other hand, unlike silica, it has solubility in various solvents, ensuring excellent processability.
The solubility of polysilsesquioxane is similar to that of general D-type silicone polymer, depending on the type, structure and molecular weight of the polymer, but polysilsesquioxane is soluble in ordinary organic solvents. It is excellent, and in the case of an oligomer having a molecular weight of several thousand, it is soluble in ethyl alcohol. Polysilsesquioxane has high transparency from the visible light region to the ultraviolet region as well as the optical communication region.
The refractive index of polysilsesquioxane is determined by the substitution product, and polymethylsilsesquioxane is suitable as having a refractive index similar to sebum. Polymethylsilsesquioxane has a refractive index of 1.42, which is the lower of the silsesquioxane polymers, and polyphenylsilsesquioxane has a value of 1.60.
Polymethylsilsesquioxane usable in the present invention is the same or similar to those disclosed in US Pat. Nos. 4,528,390 and 6,376,078, etc. It is a substance that is known enough to be purchased and used by leading traders on a daily basis, and is a substance that is currently commercialized and used in cosmetics and the like.
Since the composite particles according to the present invention are completely dispersed with primary particles in an aqueous dispersion and then coated with PMSQ silicone resin, excellent dispersibility is maintained from the powder mixing system to the dispersion or emulsification system.

  In addition, various surface treatments are possible using surface silanols distributed on the surface of the composite particles. The effects expected as a cosmetic product of the composite particles according to the present invention are superior to existing silica-coated titanium dioxide (MAXLIGHT TS or CONCELIGHT WP) by improving the texture and dispersibility of the highly cohesive particulate titanium dioxide. The characteristics of white pigments can be imparted.

  In addition, the silicone resin thin film layer on the surface of the composite particles is almost the same as the refractive index of sebum, and after makeup, the wetness by sebum prevents the whiteness and covering power from decreasing, and the makeup persistence is enhanced. Later, it has the advantage that the color does not become rich.

  The ratio of the core to the jacket can be within a range of 1: 0.05 to 0.35 by weight. When the ratio of the above core: jacket is less than 1: 0.05 by weight, the ratio of the jacket, that is, the coating amount of polymethylsilsesquioxane coated on the titanium dioxide core is very small, and it is applied to cosmetics. The problem that the whiteness and covering power are reduced due to the wetting of sebum on the skin cannot be prevented. On the contrary, the ratio of the core to the jacket exceeds 1: 0.35 by weight. In this case, the titanium dioxide cannot function as a pigment.

  The method for producing silicone resin-coated titanium dioxide composite particles according to the present invention includes (1) a first raw material preparation stage in which titanium dioxide is dispersed in water to prepare a first raw material, and (2) polymethylsilsesquioxane is alkalinized. A second raw material preparation step of preparing a second raw material by dissolving in an aqueous solution; (3) charging the second raw material into the first raw material and stirring for 3 to 4 hours in a temperature range of 50 to 70 ° C. And (4) a second reaction stage in which an aqueous acid solution is introduced into the product obtained from the first reaction stage and polymerized, and (5) after the reaction, It is characterized by comprising a post-treatment stage of standing for 30 hours and then washing with water, filtration, dehydration, drying and pulverization.

  The first raw material preparation stage (1) is to disperse titanium dioxide that will function as a core in water.

  The second raw material preparation step (2) is to dissolve polymethylsilsesquioxane, which will function as a jacket, in an alkaline aqueous solution.

At this time, the aqueous alkali solution is preferably an aqueous sodium hydroxide solution having a concentration of 10 to 20%.
Sodium methyl siliconate is formed by dissolution of the polymethylsilsesquioxane in the aqueous sodium hydroxide solution, which is also mixed with the first raw material and polymerized by addition of an aqueous acid solution to be described later. The outer envelope enclosing the particles of titanium dioxide serving as the core constituting the core.

When the concentration of the aqueous sodium hydroxide solution is less than 10% as the alkaline aqueous solution, there is a problem that polymethylsilsesquioxane cannot be sufficiently dissolved. Conversely, when the concentration exceeds 20%, the remaining sodium There is a problem that it is difficult to control ions.
The solid powder content of the second raw material obtained from the second raw material preparation stage is preferably 5 to 15% by weight.
When the content of the solid powder of the second raw material is less than 5% by weight, the coating ratio, that is, the coating amount of polymethylsilsesquioxane coated on the titanium dioxide core is very small. The problem of reduced whiteness and covering power due to wetting of sebum cannot be prevented. On the other hand, if it exceeds 15% by weight, MSQ may be polymerized and coated on the surface of titanium dioxide. There is a problem that cannot be done.

  In the first reaction step (3), the second raw material is added to the first raw material, and the mixture is heated in a temperature range of 50 to 70 ° C. for 3 to 4 hours with stirring. Here, when the heating temperature is less than 50 ° C. or the reaction time is less than 3 hours, there is a problem that the titanium dioxide surface cannot be coated, and on the contrary, the heating temperature exceeds 70 ° C. If the reaction time exceeds 4 hours, the polymerization of the monomer cannot be normally achieved.

The second reaction stage of (4) is to polymerize the product obtained from the first reaction stage by introducing an acid aqueous solution.
At this time, the acid aqueous solution in the second reaction stage is preferably a hydrochloric acid aqueous solution having a concentration of 30 to 40%.
When the concentration of the hydrochloric acid aqueous solution as the acid aqueous solution is less than 30%, there is a problem that it is not neutralized. Conversely, when it exceeds 40%, there is a problem that the amount of the hydrochloric acid aqueous solution is excessively acidified. obtain.

The post-treatment stage of (5) is to stand for 20 to 30 hours after the reaction, and then wash with water, filter, dehydrate, dry and grind.
Such a post-treatment stage can be understood as a general process for recovering the product composite particles of the present invention from the reaction mixture after the reaction.
A cosmetic composition comprising silicone resin-coated titanium dioxide composite particles according to the present invention comprises dimethicone, cyclomethicone, hexyl laurate, octyldodecyl stearoyl stearate, dimethicone acrylate copolymer, PEG9 dimethicone, distearyl dimonium chloride ( Distantyldimonium Chloride), bentonite (bentonite is a powder component, but if it absorbs oil, it is gradually classified as a special oily component used in an emulsion stabilizer), palmitic acid and two or more of these Selected from the group consisting of 40-50% by weight of an oily component selected from the group consisting of a mixture and talc, iron oxide black, iron oxide red, iron oxide yellow and mixtures of two or more thereof Powder component 1 5 to 15% by weight of an aqueous component selected from the group consisting of glycerin, 1,3-butylene glycol or a mixture thereof; It is characterized by including water as the remaining amount.
The cosmetic composition according to the present invention having the above-described configuration is a kind of so-called 'liquid foundation', and currently has the same or similar dosage form as a leading manufacturer in Japan and overseas. It is well-known so that it can be purchased and used on a daily basis.

  Dimethicone, cyclomethicone, hexyl laurate, octyldodecyl stearoyl stearate, dimethicone acrylate copolymer, PEG9 dimethicone, distearyldimonium chloride (Distearydimonium Chloride), bentonite, palmitic acid and two or more thereof When an oily component selected from the group consisting of a mixture of the above is used in an amount of less than 40% by weight based on the total cosmetic composition, there is a problem that the texture of use decreases, and on the contrary, when it exceeds 50% by weight There is a problem that the stabilization of emulsification cannot be ensured.

  The powder component selected from the group consisting of talc, iron oxide black, iron oxide red, iron oxide yellow and a mixture of two or more thereof is less than 1% by weight based on the total cosmetic composition However, when the amount exceeds 10% by weight, there is a problem due to excessive coloring.

  When the silicone resin-coated titanium dioxide composite particles are used in an amount of less than 5% by weight based on the total cosmetic composition, there is a problem that the titanium dioxide pigment characteristics cannot be exhibited. When exceeding the above, there is a problem that gives the impression of artificial makeup with excessive covering power.

  When the aqueous component selected from the group consisting of glycerin, 1,3-butylene glycol or a mixture thereof is used in an amount of less than 5% by weight based on the total cosmetic composition, the use texture is deteriorated. On the contrary, when it exceeds 15% by weight, there is a problem that emulsification safety cannot be ensured.

  Hereinafter, desirable practical examples and comparative examples of the present invention will be described.

  The following examples are for illustrating the present invention and the present invention is not limited thereto.

Example 1
150 g of titanium dioxide was added to 2000 g of purified water and dispersed therein to produce a titanium dioxide dispersion as the first raw material. Separately, 50 g of polymethylsilsesquioxane (TOSPARAL 2000B) manufactured by Toshiba Corporation was dissolved in 450 g of a 15% aqueous sodium hydroxide solution to obtain 10% sodium methylsiliconate as the second raw material. Manufactured.
The second raw material was added to the first raw material and heated to 60 ° C. with stirring. Thereafter, 170.86 g of 36% hydrochloric acid aqueous solution was added for polymerization, and the reaction product was allowed to stand for about 1 day, followed by washing with water, filtration, dehydration, drying, and pulverization. Composite particles (PMSQ 25% composite particles) were obtained.

Example 2
180 g of titanium dioxide was added to 2400 g of purified water and dispersed therein to produce a titanium dioxide dispersion as the first raw material. Separately, 20 g of polymethylsilsesquioxane (TOSPARAL 2000B) manufactured by Toshiba Corporation was dissolved in 180 g of a 15% aqueous sodium hydroxide solution to obtain 10% sodium methylsiliconate as the second raw material. Manufactured.
The second raw material was added to the first raw material and heated to 60 ° C. with stirring. Thereafter, 68.34 g of 36% hydrochloric acid aqueous solution was added for polymerization, and the reaction product was allowed to stand for about 1 day, followed by washing with water, filtration, dehydration, drying and pulverization, and the silicone resin-coated titanium dioxide according to the present invention. Composite particles (PMSQ 10% composite particles) were obtained.

Example 3
180 g of titanium dioxide was added to 2400 g of purified water and dispersed therein to produce a titanium dioxide dispersion as the first raw material. Separately, 10 g of polymethylsilsesquioxane (TOSPARAL 2000B from Toshiba) was dissolved in 90 g of 15% aqueous sodium hydroxide to produce 10% sodium methylsiliconate as the second raw material. did.
The second raw material was added to the first raw material and heated to 60 ° C. with stirring. Thereafter, 34.17 g of 36% hydrochloric acid aqueous solution was added for polymerization, the reaction product was allowed to stand for about 1 day, washed with water, filtered, dehydrated, dried and pulverized, and then the silicone resin coated titanium dioxide according to the present invention was used. Composite particles (PMSQ 5% composite particles) were obtained.

Test example 1
In order to compare the size of the particles of titanium dioxide (Comparative Example 1) used in the production of the first raw material in Example 1 and the composite material of Example 1 above, the particle size analyzer (MALVERN) MASTERSIZER 2000 (product of MALVERN, UK) was used to perform particle size analysis, which is a physical property.
The results are shown in FIG. (Dispersant; ethyl alcohol, result unit; volume)

  As shown in FIG. 1 and Table 2, the particle size distribution was not particularly different, and it was confirmed that the particle size was slightly increased in the section of D90 or more.

  Thereby, the improvement of the fluidity / spreading property of the composite particles according to the present invention can be expected, and the improvement of the smooth particle texture can be expected.

Test example 2
The results of analyzing the morphology of the composite particles of Example 1 and the particles of uncoated titanium dioxide (Comparative Example 1) used in the production of the first raw material in Example 1 with a scanning electron microscope (SEM). It is shown in FIG.

  As shown in FIG. 2, it was confirmed that a PMSQ film was formed on the surface of the titanium dioxide particles.

Test example 3
Particles composed only of the composite particles of Example 1 and polymethylsilsesquioxane (TOSPARAL 2000B manufactured by Toshiba) used in the manufacture of the second raw material in Example 1 above. (Comparative Example 2) and the like were confirmed through thermal analysis (FIG. 3) and infrared spectroscopic analysis (FIG. 4) to determine whether or not a PMSQ jacket could be formed.

  As shown in FIGS. 3 and 4, it was confirmed that the PMSQ film was formed in the same pattern as in Comparative Example 2.

Test example 4
In order to measure the change in optical characteristics due to wetting of the sebum component, 8% and 16% of CTG (capryl / capryl triglyceride), which is the main component of sebum, was used as it was in Example 1 and Comparative Example 1. %, And the change in reflectance due to wetting by CTG was measured.
The results are shown in FIG.
The reflectance was Minolta CM-2000, the test example not containing CTG was dry compression (Dry compression molding), and the test example containing CTG was wet compression (Wet compression molding).
As shown in FIG. 5, in the case of the uncoated titanium dioxide of Comparative Example 1, the reflectance decreased as it was wetted by CTG.
This causes a decrease in makeup persistence deteriorated by sebum, but in the case of Example 1 (composite particles) according to the present invention, it was confirmed that the makeup persistence was improved with almost no change in the reflectance distribution. .

Example 4
The composite particles obtained in Example 1 were surface treated with triethoxycaprylylsilane (AES).
(TiO2 / PMSQ / AES) (Coating amount: 3% by weight, coating method: AES and solvent were mixed and sprayed onto TiO2 / PMSQ, which was dried at 150 ° C. for 2 hours for surface treatment.)

Example 5
The composite particles obtained in Example 1 were surface-treated with cetyl dimethicone (CD; Cetyl Dimethicone).
(TiO2 / PMSQ / CD) (Coating amount: 2% by weight, coating method: CD and solvent were mixed and sprayed onto TiO2 / PMSQ, which was dried at 150 ° C. for 2 hours for surface treatment. .)

Example 6
The composite particles obtained in Example 1 were surface-treated with triethoxysilylethylpolydimethylsiloxyethylhexyl dimethicone (SDS; Tridimethylsilylethylhexyl Dimethicone).
(TiO2 / PMSQ / SDS) (Coating amount: 3% by weight, coating method: SDS and solvent were mixed and sprayed onto TiO2 / PMSQ, which was dried at 150 ° C. for 2 hours for surface treatment.)

Example 7
The composite particles obtained in Example 1 were converted into an acrylate / tridecyl acrylate / triethoxysilylpropyl methacrylate / dimethicone methacrylate copolymer (SAS; dimethicone acrylates / triethylylpropylene methacrylate). Surface treatment was performed using a product-a product described in ICID standards.
(TiO2 / PMSQ / SAS) (Coating amount: 3% by weight, coating method: SAS and solvent were mixed and sprayed onto TiO2 / PMSQ, which was dried at 150 ° C. for 2 hours and surface-treated).

The surface treatment agent used in the above Examples 4 to 7 was applied to further impart characteristics different from those of the composite particles according to the present invention. The composite particles according to the present invention are polymethylsilsesquioxane (PMSQ). ) Si-R and Si-OH are mixed and distributed, so that they are inherently amphiphilic and water-acidic, and can contribute to emulsion stabilization in a water-in-oil (W / O) emulsification system. Various surface characteristics can be imparted using Si-OH on the surface.
That is, in the case of the above Experimental Example 4, the water repellency and dispersibility of the particles can be further improved by the surface treatment, and in the case of the Experimental Example 5, the surface treatment can further increase the soft feeling of use, the adhesion feeling, and the dispersibility. In the case of Example 6, the surface treatment can give a soft feeling of use to further enhance the dispersibility, and in the case of Example 7, the emulsion can be given an emulsion dispersibility by the surface treatment. Can be further increased.

Comparative Examples 3 to 6
Comparative Examples 3 to 6 were carried out for comparison with the above-mentioned Experimental Examples 4 to 7 according to the present invention, and were not coated with PMSQ in place of the composite particles according to the present invention. Example (Comparative Example 3) of surface treatment with a dimethicone / methicone copolymer (Product of Shinkoshi Co., Ltd.-Product described in ICID standard), Example of surface treatment of particles of Comparative Example 1 (Comparative Example 4), Comparison It is the example (comparative example 6) which surface-treats the particle | grains of Example 1 (amino acid propyl dimethicone) and the example (surface of comparative example 5) which surface-treats the particle | grains of triethoxycapryl silylsilane (Triethoxycaprylylsilane).

Experimental example 1
Except for the use of Examples 4 to 7 and Comparative Examples 3 to 6, the remaining foundation components were the same, and the formulations (units:% by weight) shown in Tables 3 and 4 were used to produce liquid foundations.

The manufacture of the liquid foundation using the prescriptions in Tables 3 and 4 is as follows.
First, the oil component was uniformly mixed, dissolved and heated to 80 ° C. Next, the powder component was mixed and mixed with the oil component, and the temperature was maintained at 80 ° C. to obtain a continuous phase. The aqueous component was also mixed uniformly and heated to 80 ° C.
Next, the mixture of the aqueous components was gradually administered to the continuous phase and emulsified using a homogenizer.
Finally, after the emulsification was completed, it was frozen in a hot water bath to 35 ° C. and then air-cooled to room temperature.

The liquid foundation as the obtained cosmetic composition was measured for physical properties using in vitro SPF (model SPF290 analyzer; manufacturer: Optometrics USA INC), and the results are shown in FIG.
Here, a sun cream was made using the same amount (10%) of titanium dioxide not coated with in vitro SPF and titanium dioxide coated with 25% of polymethylsilsesquioxane, and the UV blocking value was specified by the in vitro test method. .
This data confirmed that the TiO2 / PMSQ has a high SP blockage value, even though the pure titanium dioxide content is 25% less, and is evenly applied to the skin by polymethylsilsesquioxane coating.
In addition, in order to compare the uniformity and the size of water-liquid particles, it is measured with an optical microscope, and the separation state is evaluated by changing the temperature from 45 ° C to 4 ° C for 1 month and 3 months. The results are shown in Table 5 below.

As a result of synthesizing the above practical examples, according to the present invention, it is possible to produce titanium dioxide composite particles coated with polymethylsilsesquioxane, which is an ordinary dispersion of titanium dioxide as primary particles in an aqueous dispersion. It was confirmed that when the polymethylsilsesquioxane resin was coated after the pigment particles were completely dispersed, excellent dispersibility was maintained in any state from the powder mixing system to the dispersion or emulsification system.
Various surface treatments are possible using the surface silanol groups distributed on the surface of the composite particles according to the present invention, and when applied to cosmetics, the texture and dispersibility of titanium dioxide with strong cohesiveness can be enhanced, The silicone resin coating layer on the surface of the particles is almost the same as the refractive index of sebum, and it is possible to prevent the decrease in whiteness and covering power by wetting with sebum after makeup, and to obtain results such as improvement in the speed of decorative paper. confirmed.

What was demonstrated above is only one Example for implementing the silicone resin coating titanium dioxide composite particle by this invention, its manufacturing method, and the cosmetics composition containing this.
The present invention is not limited to the above-described embodiments, and various modifications can be made by anyone having ordinary knowledge in the field to which the present invention belongs within the scope of the present invention without departing from the gist of the present invention. Changes can be made.

  INDUSTRIAL APPLICABILITY The present invention can be applied to the field relating to a method for producing silicone resin-coated titanium dioxide composite particles and a cosmetic composition containing the same.

Claims (4)

A silicone resin-coated titanium dioxide composite particle production method comprising: a core composed of titanium dioxide particles; and a jacket containing polymethylsilsesquioxane surrounding the core,
(1) a first raw material preparation step of preparing a first raw material by dispersing titanium dioxide in water;
(2) a second raw material preparation step of preparing a second raw material by dissolving polymethylsilsesquioxane in an alkaline aqueous solution;
(3) a first reaction step in which the second raw material is added to the first raw material and heated for 3 to 4 hours in a temperature range of 50 to 70 ° C. with stirring;
(4) a second reaction step in which an aqueous acid solution is introduced into the product obtained from the first reaction step and polymerized;
(5) After the reaction, after being left for 20 to 30 hours, a post-treatment step of washing, filtering, dehydrating, drying and pulverizing;
A method for producing silicone resin-coated titanium dioxide composite particles, comprising:   2. The method for producing silicone resin-coated titanium dioxide composite particles according to claim 1, wherein the alkaline aqueous solution in the second raw material preparation stage is a sodium hydroxide aqueous solution having a concentration of 10 to 20%.   The method for producing titanium resin-coated titanium dioxide composite particles according to claim 1 or 2, wherein the second raw material obtained from the second raw material preparation stage has a solid powder content of 5 to 15 wt%. The method for producing silicone resin-coated titanium dioxide composite particles according to any one of claims 1 to 3, wherein in the second reaction stage, the aqueous acid solution is an aqueous hydrochloric acid solution having a concentration of 30 to 40%.

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